This invention relates generally to an armature assembly for a selectively engageable and disengageable coupling such as an electromagnetic clutch or brake.
Newton U.S. Pat. No. 4,493,407 discloses a typical electromagnetic clutch in which a slotted armature disc is connected to a driven hub by a mounting plate and is adapted to be attracted into engagement with a driving rotor when an electromagnet is energized. The armature disc is connected to the mounting plate by a series of leaf springs which couple the armature disc and the mounting plate for rotation in unison while allowing the armature disc to move toward and away from the rotor when the electromagnet is energized and de-energized.
Another type of armature assembly is disclosed in Booth U.S. Pat. No. 5,150,779. In that armature assembly, a resiliently yieldable plastic web acts to connect a low magnetic reluctance armature disc for rotation with the driven hub. The web flexes axially in order to permit the armature disc to move toward and away from the rotor when the clutch is engaged and disengaged.
Impact noise is produced when the armature disc is initially snapped into engagement with the rotor. Noise also is produced by vibration which occurs during slippage of the armature disc and when the disc is disengaged from the rotor.